either way, it would be much faster if you created the array at once using some maths rather than create three massive intermediary arrays with .collect and .lace, especially if you want to work with arrays that large

Thanks, @brianlheim , for reacting. Yea, what you say sounds plausible. My problem is that I don't know the maths to create an array that would allow to generate interleaved data for multichannel... I'll think about it better and see if I can ask a better question.I was halph asking also because the crashes I see seem linked to the "garbage collector" work done a few months ago. I even get "grey count errors" if I run the code in context. But seems totally indeterministic....